The degree diameter problem involves finding the largest graph (in terms of the number of vertices) subject to constraints on the degree and the diameter of the graph. Beyond the degree constraint there is no restriction ...

In this paper we show that a model for inertial mass (quantised inertia) can be derived exactly and simply by assuming that the property of inertia is caused by gradients in the energy in the Unruh radiation field seen ...

Absence of gradient and Nernstian equilibrium stripping (AGNES) senses the free ion concentration of Zn(II) in solutions containing different ligands, being unaffected by the lack of reversibility of the Zn2+/Zn0 couple ...

A graph G is called edge-magic if there is a bijective function f from the set of vertices and edges to the set {1, 2, . . . , |V (G)| + |E(G)|} such that the sum f(x) + f(xy) + f(y) for any xy in E(G) is constant. Such ...

Statistical analysis of point processes often assumes that the underlying process is isotropic in the sense that its distribution is invariant under rotation. For point processes on ℝ2, some tests based on the K‐ and nearest ...

Let R be a commutative ring with nonzero identity and let Z(R) be its set of zero divisors. The zero-divisor graph of R is the graph T(R) with vertex set V(T(R))=Z(R)*, where Z(R)*=Z(R)\{0} , and edge set E(T(R))={{x,y}:x·y=0} ...

We consider a planar autonomous real analytic differential system with a monodromic singular point p. We deal with the center problem for the singular point p. Our aim is to highlight some relations between the divergence ...

Understanding inter- and intra-specific plant interactions and competition over water is challenging because of the lack of effective approaches for accessing and monitoring root distribution and activity. In this context, ...

Edge-distance-regularity is a concept recently introduced by the authors which is similar to that of distance-regularity, but now the graph is seen from each of its edges instead of from its vertices. More precisely, a ...

This paper deals with the problem of location and existence of limit cycles for real planar polynomial differential systems. We provide a method to construct Poincaré-Bendixson regions by using transversal curves, that ...